Technical Abstract:
Exotic pathogen introductions continue to escalate commensurate with increasing international trade and travel. Discovery of a new disease should be expeditiously followed by delimiting surveys to assess distribution and incidence. Specific, relevant survey protocols are used to ensure reliable data to determine the appropriate regulatory response. For example, surveys of citrus canker and plum pox virus (PPV), both exotic diseases, indicated a restricted distribution and a low incidence in Florida and Pennsylvania, respectively. Eradication programs were thus deemed feasible and were established. In contrast, surveys determined that citrus huanglongbing in Florida, soybean rust in the mid west, and PPV in Canada were widespread when discovered precluding an eradication strategy, so other disease mitigation approaches were deployed. Sometimes eradication is still desirable even if the disease is widespread but the incidence of infection is low. In such cases, stepwise eradication protocols can be deployed based on surveys to determine incidence thresholds, which, when exceeded result in removal of the planting (or only infected plants if incidence is below the threshold). Thresholds are decreased over time as multiple cycles of removal occur, allowing the industry to survive while suppressing the disease until more stringent eradication protocols are feasible.